Work-holding-foot mechanism



J. P. W EI S. WORK HOLDING FOOT MECHANISM. APPLICATION FlLED JAN. 2,1919.

1,419,087. PatentedJune 6,1922.

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Jenn. rETEn WEIS, or NYACK, NEW YORK, ASSIGNOR or ONE-HALF 'romn'rnorom- TANSEWING- MACHINE CORPORATION, or novnia, DELAWARE, aoonronarron or DELAWE.

WOBK-HOLDING-FOOT MECHANISM.

Specification of Letters Patent.

Patented June e, 1922.

Original applicationfiled October 16, 1914, Serial No. 867,005. Dividedand this application filed Jannary-2, 1919.- Serial No. 269,273.

To all whom alt may concern:

Be it known that I, J OHN PETER Wins, a citizen of the United States,residing at Nlyack, in the county of Rockland and State of New York,have invented certain new and useful Improvements in Work-Holding- FootMechanisms, of which the following is aspecification.

This invention is an improvementin w0rkholding. foot construction forsewing machines. The object of the invention is to securea simple andconvenient work-holding foot which shall automatically adjustitselt tovariations in thickness of goods fed to the stitch-for1ninginstrumentalities while the needle is operating at high speed, and beoperable to glide over the goods in a traveling sewing machine.

In the accompanying drawings forming part hereof;

Fig. 1 is a front elevational perspective ol the front end portions ofthe upper and under arm of a sewing machine head embodying thisinvention and. showing the stitch-forming instrumentalities, theworkholding foot being omitted for greater clearness. I

Fig. 2 is. a front elevation of what is shown in. Fig. 1, with thework-holding foot. in place.

Fig. 3.is a perspective view of the needlebar-actuating crank removed.

Fig. l i a perspective view'of the needleholder guide detached.

Fig. 5 shows the needle holder in plan and sideelevation.

Fig. 6 is a detailed view partially in section at line 66 to Fig. 5 ofthe needle holder and co-operating parts.

This application is a division of my pending application Serial No.867,005, filed October 16, 1914.

Referring to the drawings, A represents the upper arm and A the underarm of a sewing machine head. The under arm carries an oscillatinglooperL on a looper shait M. The upper arm carries a needle-driveshaft'D on the front end of which is a crank 1 having on its rearwardside about midway between its ends a right-angular tubular socket 2 thatopens through the front wall of the crank. The latter is madeapproximately as the segment 01 a circle and is wider at one end inorder to serve as a counterbalancing weight than it is at its narrowerend from thefront side of which a crank pin 3 projects. The crank socketis secured on the front end of the drive shaft D by pins 00. On crankpin 3 of this sideweighted crank there is pivoted the upper end of adependent pitman 1 the bottom end of which is pivoted at 5 to a slidingneedle holder 6 holding the shank of the needle B. In the under endportion of the upper arm A there is socketed a dependent approximatelyL-shaped needle-holder guide which is generally indicated by G (Fig. 4)having an approximately half-round shank 7; at the foot of the shank alaterally projecting shoulder 8 from the outer end portion oi whichthere projects downwardly a crosssectionally l -sha-ped bar 9 to thefree edge of the flange 10 of which there is'fixed a detachablecover-plate 11 by means of screws 12. By this construction a guideway 13is formed tor one end of the needle holder. Shank 7 is provided with adependent cross-sectionally round needle-holder guide pin 14 that isparallel to and opposite the lengthwise opening of the guideway 13. 1

Crank 1 and crank pin 3 are formed with a lubricant duct 15 and theguide pin 14 is formed from its upper end which is flush with the upperend of the shank 7 with a lengthwise-extending lubricant duct 16 thathas radial wall openings 17 serving as lubricant ducts. v

That portion of the guide G which has the lengthwise-extending guideway13 is mounted inwardly towards the trunk T of the head, the guide pin14' being intermediate said portion of the guide G and the needle. Theneedle guide has a vertical bore 18 slidahle on the guide pin 14 and anintegral guide wing 19 that slides in the vertical guideway 13. Thus theneedle holder is kept from. oscillation in a horizontal plane during itsvertical reciprocations. At that end of the needle holder which isopposite the vertical bore 18 and guide wing 19 the needle holder isprovided with a vertical bore 20 for reception of the needle shank.Between the bores 18 and 20 the needle holder is provided with a siderecess 21 so that the bore 18 and the guide wing 19 are in one fork armand the needle-hole bore 20 in another fork arm of the needle holderwhich thus straddles the bottom end of pit-- man 42, such bottom endplaying in the recess 21 which is spanned by the pivot pin 5 by means ofwhich the bottom end of the pitman and the needle holder are looselyconnected together. The needle holder has a horizontally-extending bore5 for the pintle pin 5; and has a horizontal bore 22 throughout itslength, at the front side of the web 22 The bore 22 constitutes a threadpas sage. The inward end of the recess 21 inter sects this threadpassage so that the threadnipper spring 23 may pass through the inwardend portion of the recess 21 between the foot of the pitman and thethread or.

threads in the thread passage 22 to hold the needle thread whenever andas may be required.

The work-holding foot construction comprises a dependent bracket havinga shank 24- that is secured by a screw 25 to the front end of the upperarm A, the shank 24: terminating in an angular outwardly-projecting foot25 to the lower end of which by a pivot-.

screw 26 there is pivoted a work-holdingfoot carrier 27 that extendsover the throat plate 28 The outward end of the work holding-footcarrier is bent upwardly and inwardly at 28 over the upper side of theangular foot 25 The free end of the bend at 28 is provided with anadjusting screw 29 the inward end of which impinges on the upper wall ofthe foot 25*. A suitable spring 30 is interposed between the carrier 27and the under side of the foot 25. The spring tends to push theworlcholding foot 31 carried by its free end over the throat-platedownwardly and by adjustments of the screw 29 the work-holding foot 31may be adjusted upwardly in relation to the throat plate 28. The frontend of the work-holding foot is upturned at 32 easily to glide overgoods held down'by it by the pressure of the spring 30. This springpressure on the work-holding foot that glides over the goods when and ifthe sewing-machine head is bodily moved during stitchforming operations,is very useful whenever there are variations in the thickness of thegoods, as for example in certain ribbed goods during the sewing of whichthe foot will be lifted automatically against the resistance of thespring 30. The foot 31 has on its upper side back of its needle hole anupstanding wall 33 adjacent the back side of the needle holeand forminga lateral abutment for the needle when in the goods, and the feed of thegoods pulls the needlelaterally towards the wall. This is useful indiminishing needle breakage and skipping of stitches.

Emphasis is laid on the location of the pivotal connection at 26 of thepivoted end of the work foot. carrier. It is as closely adjacent theupper level of the throat plate as is consistent with the travel ofgoods across the throat plate 28, a goods way Y being formed between thethroat plate and the under side of the work-foot carrier 21. By reasonof such location, the abutment wall 33 moves practically verticallyduringthe automatic or mechanical adjustments of the work-holding foot.It will be observed in the present case that there is no feed dog ormeans through the work plate for cooperation with the foot and needle.The foot has only negligible pressure on the goods except at ribs orseams, the carrier 27 being set so that the goods travel over the workplate in very gentle contact with the foot which is movable between thework plate and the un-- der end of the dependent guide G.

The bracket shank 24 while adjustable endwise to vary the workingposition of the work holding foot above the throat plate,

is fixed when in adjusted position. This stationary bracket constitutesthe holder or carrier of the work holding foot which while movable onthe lower end of the bracket has no reciprocating movement incooperation with a feed dog, as is the case in most sewing machines.There is no feeding device in the sewing machine head herein shown; and"in machines in which my present invention has been incorporated, thefeed of the goods has been effected by feed rolls spaced-apart from thesewing machine head. If the work holding foot herein described werecomparable to the ordinary pressure foot of the usual sewing machine,its bracket shank 24 would have to be endwise movable in order to obtainthe rise and fall or reciprocation of the foot synchronously with themovements of a feed dog and relatively to the throatplate.

What I claim is,-

In a sewing machine the combination gular under end portion ofthebracket and p the work holding foot, the spring'functioning to holdthe foot against the upper surface of goods between the throat plate andupper stitch forming instrumentality; and

move the foot into a lower position towards the goods while the foot isupwardly movable against the tension of the spring to permit goods to befed freely between the throat plate and the foot and to prevent thespring from effecting a clamping pressure on the goods.

In testimony whereof I have hereunto set my hand this 27th day ofDecember, 1918.

JOHN PETER WEIS.

